This invention relates generally to catheter devices. More particularly, the invention relates to safety catheter devices having needlestick protection features and preferably automatic such features.
Intravenous (IV) catheters are medical devices used to obtain continuous vascular access in patients. Such a device generally consists of a hollow-bore needle stylet and an over-the-needle plastic type material catheter used to access the lumen of a blood vessel in a patient. The IV catheter is advanced into the vessel and is used for administering intravenous fluids, medications or blood products. Since the IV catheter is placed percutaneously, the hollow-bore needle stylet becomes blood contaminated and, when the blood vessel lumen is accessed, the needle-stylet becomes blood-filled.
Needlestick injuries from IV catheter stylets are in the high-risk category for potential transmission of bloodborne pathogens to the injured health care worker, since they are hollow-bore needles which are usually filled with undiluted blood. The bloodborne pathogens of greatest concern include human immunodeficiency virus (HIV), the etiologic agent of the acquired immunodeficiency syndrome (AIDS), hepatitis B virus and hepatitis C virus.
It is estimated at least 800,000 needlestick injuries from all types of needle devices occur in hospital settings each year in the United States. While nationwide data from 1995 indicate 7.3% of percutaneous injuries were from IV catheter stylets, the injury frequency is not the direct determinant of risk for infection transmission (xe2x80x9cPrevention, Management and Chemoprophylaxis of Occupational Exposure to HIVxe2x80x9d Advances in Exposure Prevention 1997; pp. 14-25). The type of device responsible for a percutaneous injury is a critical determinant of the potential for infection transmission. When the source patient is infected, devices which introduce a larger volume of blood inoculum into the injured health care worker are more likely to transmit infection. (Cardo D M, et al. A case-control study of HIV seroconversion in health care workers after percutaneous exposure. N Engl J Med 1997; 337: 1485-90). Injuries from hollow-bore blood-filled needles introduce a greater volume of blood inoculum into the injured health care worker than either non-blood-filled needles or solid-core needles. Twenty-five percent (25%) of percutaneous injuries from the above 1995 nationwide data were in the high-risk (blood-filled hollow-bore needle) category, and approximately 25% of the high-risk injuries were related to IV catheter insertion. An analysis of all devices causing percutaneous injuries indicated that IV catheter stylets were the number one cause of high-risk needlestick injuries (Injuries from vascular devices: High risk and preventable. Advances in Exposure Prevention 1998; 3:37-47). A study of health care workers with documented occupationally acquired HIV infections after percutaneous exposure to HIV-infected blood indicated 91% of seroconversions were from hollow-bore needle injuries and a high-risk factor for HIV seroconversion was a needle previously in a patient""s vein or artery (a blood-filled needle) (Cardo D M, et al. N Engl J Med 1997; 337: 1485-90). These data indicate safety IV catheters are a high priority for safety devices in the health care setting.
An analysis of injuries from the 1995 nationwide data above indicates most would have been potentially preventable with use of safety devices (Prevention, Management and Chemoprophylaxis of Occupational Exposure to HIV. Advances in Exposure Prevention 1997; pp. 50-51). The Occupational Safety and Health Administration (OSHA) Bloodborne Pathogen Standard requires that engineering controls, including safety devices, be used along with other methods to reduce occupational exposure to bloodborne pathogens.
The Centers for Disease Control and Prevention (CDC) recommends xe2x80x9cthat safety devices include safety features that activate automatically and do not rely on activation by health care workersxe2x80x9d (CDC Morbidity and Mortality Weekly Report (MMWR) Jan. 17, 1997, pp. 21-25). This preferred type of safety feature is passive, such that no activation by the user is necessary (xe2x80x9cactivexe2x80x9d safety features require activation by the user, which depends on user compliance, and are therefore less desirable). An analysis of nationwide data support the recommendation for passive safety features: over 50% of injuries from safety IV catheter stylets occurred after placement of the IV catheter (i.e., after use of the stylet, or during or after disposal of the stylet) and most of these injuries occurred because the user did not place the stylet into its locked safety position (Advances in Exposure Prevention 1998; 3:37-47).
As of June 1998, only two types of safety IV catheters are marketed worldwide; however, neither adequately meets the CDC requirements. Disadvantages of both catheters include: activation of the safety feature depends on the health care worker""s compliance with a specific IV catheter insertion/activation technique, and the safety feature can be bypassed if the catheter is used incorrectly, resulting in an unprotected contaminated needle tip. Of further significance, the insertion/activation techniques required for these catheters add additional steps and/or complexity to the IV catheter insertion process compared to standard non-safety IV catheters.
The need for improvement in IV catheters is apparent. The safety catheter of the present invention advantageously meets the CDC recommendation xe2x80x9cthat safety devices include safety features that activate automatically and do not rely on activation by health care workers.xe2x80x9d In addition, the insertion/activation technique required for the present invention advantageously does not add steps and/or complexity to the process of IV catheter insertion.
The shortcomings of the prior art are overcome and additional advantages are provided through the provision of a safety intravenous catheter assembly for use with a needle. The assembly preferably comprises the following. A catheter hub has an axial bore extending through the catheter hub. A needle cover has a first end of the needle cover insertable in the axial bore and a second axial bore extending through the needle cover and co-axial with the axial bore. A notch extends outwardly in the axial bore of the catheter hub. A notch clip is joined with the needle cover and is positionable to engage the notch of the catheter hub. The notch clip can engage a side of the needle and the notch and lock the catheter hub in engagement with the needle cover when the needle cover is inserted in the axial bore and the needle is inserted in the second axial bore at least adjacent or past a distal portion of the notch clip. Finally, the notch clip disengages the notch and enables the catheter hub to pass out of engagement with the needle cover when the needle is located in the second axial bore prior to the distal portion of the notch clip.
Another feature of the invention relates to a method for using a safety intravenous catheter assembly in combination with a needle. Preferably the method comprises: withdrawing the needle from a second axial bore, the second axial bore being located in a needle cover, and the needle cover including a notch clip positionable in engagement with an outwardly extending notch in a catheter hub; sliding the needle in engagement with the notch clip when withdrawing the needle from the second axial bore; forcing the notch clip into the second axial bore; and, disengaging the catheter hub from the needle cover.
Still another feature of the invention concerns practicing the method where, additionally or alternatively, the needle cover is inserted into the catheter hub and the catheter hub is locked in engagement with the needle cover wherein the locking relationship comprises engaging a side of the needle against the notch clip and maintaining the notch clip in the notch.
According to other features of the invention, there are provided automatic and/or continuous means for positioning the notch clip, particular notch and notch clip configurations, and a stop assembly to limit withdrawing of the needle from the needle cover.